Quoting Tvrtko Ursulin (2019-07-03 12:23:52) > > On 03/07/2019 10:17, Chris Wilson wrote: > > During post-reset resume, we call intel_mocs_init_engine to reinitialise > > the MOCS registers. Suprisingly, especially when enhanced by lockdep, > > the acquisition of the forcewake lock around each register write takes a > > substantial portion of the reset time. We don't need to use the > > individual forcewake here as we can assume that the caller is holding a > > blanket forcewake for the reset&resume and the resume is serialised. > > > > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > --- > > drivers/gpu/drm/i915/gt/intel_mocs.c | 15 +++++++++------ > > 1 file changed, 9 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/gt/intel_mocs.c b/drivers/gpu/drm/i915/gt/intel_mocs.c > > index ae6cbf0d517c..290a5e9b90b9 100644 > > --- a/drivers/gpu/drm/i915/gt/intel_mocs.c > > +++ b/drivers/gpu/drm/i915/gt/intel_mocs.c > > @@ -346,6 +346,9 @@ void intel_mocs_init_engine(struct intel_engine_cs *engine) > > unsigned int index; > > u32 unused_value; > > > > + /* Called under a blanket forcewake */ > > + assert_forcewakes_active(uncore, FORCEWAKE_ALL); > > + > > Assert is strictly speaking a bit weak since forcewake status can > theoretically change until the actual access below. But in our current > code we indeed hold it for the whole reset. You want to distinguish between an explicit hold by the caller and the auto. > I don't have any actual ideas on how to fundamentally improve the > assert. Thought to have it after the writes is the only thing which came > to mind. Thoughts? I definitely prefer having it upfront to document the function preconditions, and so would prefer if the assert actually did assert an explicit forcewake as it is meant to do :) -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
